Children born to HIV-1 infected mothers were immunized at birth, 1, 3, and 5 months with one of 3 doses of recombinant gp120 vaccines prepared from SF-2 or MN strains of HIV-1. 126 children proved to be HIV-uninfected, 21 received adjuvant only. Vaccine recipients developed lymphoproliferative responses on 2 or more occasions more often to homologous HIV-1 antigens than did adjuvant recipients (56% vs 14%, p<0.001). Responses were appreciated at 2 months of age, after 2 immunizations, and maintained for more than 84 weeks after the last immunization. An accelerated immunization schedule ( birth, 2 weeks, 2 and 5 months) with the lowest dose of the SF-2 vaccine produced responses in all 11 vaccinees by 4 weeks. Responses to heterologous envelope antigens were also detected. Immune responses to vaccination is achievable at an age when some infection (perinatal and via breast milk exposure) may be prevented.